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b20 torque specs (all of them)

oemoilleaks

oemoilleaks

Member
Joined
Mar 26, 2017
Location
SoCAL
I'm currently building a big bore b20 and as I've been assembling the short block I've come to realize who woefully incomplete the green book is when it comes to torque specifications on certain parts. I've cross referenced with Clymer and Hanes books but still don't have a complete list.

I feel like there was a page someone had put together that had them all listed in one place. Did I imagine this? Is it out there?
 
Below are the torque specs I suggest.

To be honest, we normally only use a torque wrench on the engine bolts that are 3/8" in diameter and larger with the clutch bolts being the only exception as we always use a torque wrench on those. Some of the nuts and bolts are not easily accessible to a socket and torque wrench

For example, you might be able to use a torque wrench on the oil pump bolts if an offset adapter is used, but we've always hand tightened those bolts with a wrench. With the advent of Loctite, we use it on selected nuts and bolts.

All measurements are in ft/lbs.

Head bolts/stud nuts: 70-75, lightly oiled
Main cap bolt/nuts: 90, lightly oiled
Rod nuts(stock): 45, lightly oiled, stake each nut in 2 places
Cam thrust plate: 10, use Loctite
Cam nut: 75, use Loctite & stake nut in 2-3 places
Flywheel bolts: 45, use Loctite
Clutch bolts: 25, Grade 8 w/Grade 8 split lock washers
Rocker shaft bolt: 25
Crankshaft bolt: 60, use Loctite
Water pump bolts: 20-25 w/wave washers
Water pump pulley/fan bolts: 20-25 w/split lock washers
Front crankshaft seal housing bolts: 8-10 w/wave washers
Rear crankshaft seal housing bolts: 8-10, w/wave washers, use Loctite
Oil pan: 20-25
Oil pump: 20-25, use Loctite w/wave or lock washers
Breather box: 8-10 w/wave washer
Distributor base, fuel pump/block off plate: 20-25, w/wave washers, use Loctite
Motor mount bolts: 20-25 w/split lock washers
Valve cover: 8-10 w/wave washers
Intake/exhaust manifold nuts/bolts to head: 20-25 w/Belleville or wave washers

Did I forget anything?
 
Someone should make this a sticky.
I didn't use Loctite on most of these, just the crank / pulley bolt.
You think I should go back into mine?
Steve
 
sksmith said:
I didn't use Loctite on most of these, just the crank / pulley bolt.
You think I should go back into mine?
Steve
Click to expand...

That's up to you. But if you torqued everything, then you should be in good shape. Don't forget, Volvo didn't originally use Loctite. The 1st use of Loctite that I know is on the cam thrust plate bolts which are included with their timing gear kits.

FYI, the bolts of most concern would be for the flywheel, the rear main seal housing and the cam thrust plate.
 
planetman said:
Below are the torque specs I suggest.

To be honest, we normally only use a torque wrench on the engine bolts that are 3/8" in diameter and larger with the clutch bolts being the only exception as we always use a torque wrench on those. Some of the nuts and bolts are not easily accessible to a socket and torque wrench

For example, you might be able to use a torque wrench on the oil pump bolts if an offset adapter is used, but we've always hand tightened those bolts with a wrench. With the advent of Loctite, we use it on selected nuts and bolts.

All measurements are in ft/lbs.

Head bolts/stud nuts: 70-75, lightly oiled
Main cap bolt/nuts: 90, lightly oiled
Rod nuts(stock): 45, lightly oiled, stake each nut in 2 places
Cam thrust plate: 10, use Loctite
Cam nut: 75, use Loctite & stake nut in 2-3 places
Flywheel bolts: 45, use Loctite
Clutch bolts: 25, Grade 8 w/Grade 8 split lock washers
Rocker shaft bolt: 25
Crankshaft bolt: 60, use Loctite
Water pump bolts: 20-25 w/wave washers
Water pump pulley/fan bolts: 20-25 w/split lock washers
Front crankshaft seal housing bolts: 8-10 w/wave washers
Rear crankshaft seal housing bolts: 8-10, w/wave washers, use Loctite
Oil pan: 20-25
Oil pump: 20-25, use Loctite w/wave or lock washers
Breather box: 8-10 w/wave washer
Distributor base, fuel pump/block off plate: 20-25, w/wave washers, use Loctite
Motor mount bolts: 20-25 w/split lock washers
Valve cover: 8-10 w/wave washers
Intake/exhaust manifold nuts/bolts to head: 20-25 w/Belleville or wave washers

Did I forget anything?
Click to expand...


This is amazing! I second the sticky motion. Thanks Eric!
 
If I recall correctly. Volvo doesn't list all torque specs and gives an explanation at the beginning of one of the green books. Something about important bolts requiring the torque wrench and other fasteners just being tightened to a standard of the industry for that size and grade bolt.

Thanks for that great list!
 
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